Just in case anyone is interested in my newest toy; a combination: 'jump-starter"; '400 watt 240 VAC inverter'...probably not sine-wave; air-compressor; running off a 18 AH lead-acid battery; all up weight `~ 8Kg;..... bit heavy for a bike I suppose ! pressure gauge, battery meter, 240 VAC and 12 V DC charging; caveats: 18AH = 18A x 12 Volt. Hr = 216 W.H = ~ 0.5 H at 400 watts and haven't timed the compressor yet, to see if it pumps up a car tyre in T =< 5 min ;; $150 at Autobarn ; regards Rohan McLeod